Air supply system for fuel cell power generation system

Abstract

The utility model provides an air supply system for a fuel cell power generation system, and the system comprises a mixing chamber which is suitable for being communicated with an air inlet of an electric pile of the fuel cell power generation system; one end of the first air path is communicated with the external environment, and the other end of the first air path is communicated with the mixing chamber; one end of the second air path is communicated with the external environment, and the other end of the second air path is communicated with the mixing chamber; the first air compressor is arranged in the first air path; the second air compressor is arranged in the second air path; the first air cooling device is arranged on the first air path and is positioned between the first air compressor and the mixing chamber; and the humidifying tank is arranged on the second air path and located between the second air compressor and the mixing cavity, and the humidifying tank is used for humidifying and cooling air flowing into the humidifying tank.

Description

Technical Field

[0001] The utility model relates to the technical field of fuel cells, in particular to an air supply system for a fuel cell power generation system. Background Art

[0002] A fuel cell is a power generation device that converts the chemical energy of fuel (hydrogen) and oxidant (oxygen) into electrical energy through an electrochemical reaction. Since it is not restricted by the "Carnot cycle", its energy conversion efficiency is significantly higher than that of ordinary heat engines. With the gradual maturity of fuel cell technology, fuel cell systems have been widely applied in specific application fields such as vehicles, ships, drones, power stations, and combined heat and power, showing broad development prospects.

[0003] In application scenarios of fuel cell power generation systems that require high power, such as power stations and combined heat and power, the oxidant required for the electrochemical reaction usually needs to be obtained from a compressed air centralized supply system. For example, a Chinese patent application with publication number CN116826107A discloses a fuel cell power generation system that realizes the supply of air through an air supply unit (i.e., a compressed air centralized supply system), and uses the air exhaust of the fuel cell stack to passively humidify the supplied air through a membrane humidifier, and the humidity cannot be actively adjusted. The compressed air centralized supply system belongs to a complete set of equipment and needs to be purchased and installed as a whole. If a compressed air centralized supply system has been configured at the application site of the fuel cell power generation system, direct gas extraction can be considered. However, in many application sites, a compressed air centralized supply system is not configured, and additional procurement and installation are required, resulting in high costs.

[0004] Regarding the complete set of compressed air centralized supply systems, reference can be further made to the technical solutions disclosed in Chinese utility model patents with publication numbers CN201106560Y, CN201354724Y, and CN202349595U. In the existing complete set of compressed air centralized supply systems, a cold dryer is provided, so that the externally supplied compressed air is low-temperature and dry compressed air. The air compressed and heated by the air compressor is cooled down before being externally supplied, resulting in energy waste.

[0005] In order to achieve active humidification of the supplied air and enable controllable adjustment of the humidity of the supplied air, a fuel cell humidification system is disclosed in a Chinese patent application with publication number CN110571458A. It forms mixed air that meets specific humidity requirements by controlling the mixing ratio of dry air and wet air. However, the air source is still a container for storing air, that is, the air storage tanks and cylinders in a complete set of compressed air centralized supply systems. Therefore, the air supplied to the first pipeline and the second pipeline is low-temperature and dry air. The air in the second pipeline needs to enter the humidification tank to be humidified and is heated to a certain temperature by the water in the humidification tank. The water in the humidification tank needs to be heated by a first heating device, which consumes additional energy. In other words, the air is compressed and heated by the air compressor in the compressed air centralized supply system, cooled by the cold dryer, and then enters the humidification tank through the second pipeline to be heated. This process of first cooling the compressed air and then heating wastes a large amount of energy. In addition, in order to control the mixing ratio of dry air and wet air, two more proportional valves (electromagnetic proportional regulating valves or mass flow controllers) are further provided for control, which further increases the cost of the fuel cell power generation system. Utility Model Content

[0006] The main advantage of the present utility model is to provide an air supply system for a fuel cell power generation system. In the air supply system for the fuel cell power generation system, two small air compressors are used respectively for air supply and flow control of the first air path and the second air path to replace the air supply using a complete set of compressed air centralized supply systems in the prior art, and the scheme of using two mass flow controllers to control the flow of the two air paths can reduce costs.

[0007] Another advantage of the present utility model is to provide an air supply system for a fuel cell power generation system. In the air supply system for the fuel cell power generation system, the humidification tank is used for air humidification and cooling, rather than heating and warming the air using a humidification tank in the prior art. There is no longer a need to configure a heating device for heating the humidifying water in the system, and the heat of the air compressed and heated by the air compressor can be fully utilized.

[0008] Correspondingly, according to an embodiment of the present utility model, an air supply system for a fuel cell power generation system having at least one of the foregoing advantages includes:

[0009] A mixing chamber adapted to communicate with the air inlet of the stack of the fuel cell power generation system;

[0010] A first air path having one end communicating with the external environment and the other end communicating with the mixing chamber;

[0011] A second air path having one end communicating with the external environment and the other end communicating with the mixing chamber;

[0012] The first air compressor is disposed in the first air path;

[0013] The second air compressor is disposed in the second air path;

[0014] The first air cooling device is disposed in the first air path and is located between the first air compressor and the mixing chamber; and

[0015] The humidification tank is disposed in the second air path and is located between the second air compressor and the mixing chamber, wherein the humidification tank is used for humidifying and cooling the air flowing into the humidification tank.

[0016] In some embodiments, the temperature of the humidifying water in the humidification tank is not higher than the temperature of the air flowing into the humidification tank.

[0017] In some embodiments, the air supply system for the fuel cell power generation system further includes a humidifying water circulation path, a water pump, and a humidifying water cooling device, wherein both ends of the humidifying water circulation path are respectively communicated with the humidification tank, and the water pump and the humidifying water cooling device are both disposed in the humidifying water circulation path.

[0018] In some embodiments, the humidifying water cooling device is a plate heat exchanger.

[0019] In some embodiments, the air supply system for the fuel cell power generation system further includes a first temperature sensor and a second temperature sensor, wherein the first temperature sensor is disposed in the first air path and is located between the first air cooling device and the mixing chamber, and the second temperature sensor is disposed in the second air path and is located between the humidification tank and the mixing chamber.

[0020] In some embodiments, the air supply system for the fuel cell power generation system further includes a first flow meter and a second flow meter, wherein the first flow meter is disposed in the first air path, and the second flow meter is disposed in the second air path.

[0021] In some embodiments, the air supply system for the fuel cell power generation system further includes a water replenishing path, wherein the water replenishing path is communicated with the humidification tank for replenishing humidifying water into the humidification tank.

[0022] In some embodiments, the first air cooling device is an intercooler.

[0023] In some embodiments, the air supply system for the fuel cell power generation system further includes a second air cooling device, wherein the second air cooling device is disposed in the second air path and is located between the second air compressor and the humidification tank.

[0024] In some embodiments, the second air cooling device is an intercooler.

[0025] Combined with the following description and the accompanying drawings of the specification, the above and other advantages of the present utility model will be fully embodied.

[0026] The above and other advantages and features of the present utility model are fully embodied by the following detailed description of the present utility model and the accompanying drawings of the specification. Description of the Drawings

[0027] Figure 1 is a schematic diagram of an air supply system for a fuel cell power generation system according to an embodiment of the present utility model.

[0028] Figure 2 is a schematic diagram of an air supply system for a fuel cell power generation system according to another embodiment of the present utility model.

[0029] In the figure: 10, fuel cell stack; 101, air inlet; 11, first air path; 111, first air compressor; 112, first air cooling device; 113, first temperature sensor; 114, first flow meter; 115, first air filter; 12, second air path; 120, humidification tank; 121, second air compressor; 122, second air cooling device; 123, second temperature sensor; 124, second flow meter; 125, second air filter; 13, mixing chamber; 14, humidification water circulation path; 141, water pump; 142, humidification water cooling device; 15, water replenishment path; 16, drainage path. Detailed Embodiments

[0030] The following description is provided to enable a person of ordinary skill in the art to implement the present utility model. Other obvious substitutions, modifications, and variations can be contemplated by a person of ordinary skill in the art. Therefore, the scope of protection of the present utility model should not be limited by the exemplary embodiments described herein.

[0031] A person of ordinary skill in the art should understand that unless specifically indicated herein, the term "a" should be understood as "at least one" or "one or more". That is, in one embodiment, the number of an element can be one, while in other embodiments, the number of the element can be multiple.

[0032] Those of ordinary skill in the art should understand that, unless specifically stated herein, the orientations or positions referred to by terms such as "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientations or positions shown in the drawings, and are only for the convenience of describing the present utility model, rather than indicating or implying that the devices or elements involved must have specific orientations or positions. Therefore, the above terms should not be construed as limitations on the present utility model.

[0033] Referring to the accompanying drawings of the specification of the present utility model Figure 1 , an air supply system for a fuel cell power generation system according to an embodiment of the present utility model is illustrated. The air supply system for the fuel cell power generation system includes a first air path 11, a second air path 12, a mixing chamber 13, a first air compressor 111, a second air compressor 121, a first air cooling device 112, and a humidifying tank 120. Both the first air path 11 and the second air path 12 communicate with the mixing chamber 13, and the mixing chamber 13 is adapted to communicate with an air inlet 101 of a stack 10 of the fuel cell power generation system, so that the air supplied through the first air path 11 and the air supplied through the second air path 12 are mixed in the mixing chamber 13, and after mixing, it flows out of the mixing chamber 13 and further supplies to the stack 10 of the fuel cell power generation system.

[0034] The first air compressor 111 is arranged in the first air path 11 for directly obtaining air from the external environment by the first air path 11 and driving the air to flow along the first air path 11. The first air cooling device 112 is arranged in the first air path 11 and is located between the first air compressor 111 and the mixing chamber 13, so that the air compressed and heated by the first air compressor 111 can first pass through the first air cooling device 112 to be cooled down to a first set temperature, and then flow into the mixing chamber 13 for mixing. The air flowing into the mixing chamber 13 through the first air path 11 is not humidified and belongs to relatively dry air, serving as dry air for mixing. It is worth mentioning that the first air cooling device 112 can be an intercooler, a radiator or a heat exchanger. Preferably, the first air cooling device 112 is implemented as an intercooler.

[0035] The second air compressor 121 is disposed in the second air path 12, and is configured to enable the second air path 12 to directly obtain air from the external environment and drive the air to flow along the second air path 12. The humidifying tank 120 is disposed in the second air path 12 and is located between the second air compressor 121 and the mixing chamber 13, and is configured to humidify and cool the air flowing into the humidifying tank 120, so that the air compressed and heated by the second air compressor 121 can first pass through the humidifying tank 120 and be humidified by the humidifying water in the humidifying tank 120 to a set relative humidity (such as 100% relative humidity), and at the same time be cooled by the humidifying water in the humidifying tank 120 to a second set temperature, and then flow into the mixing chamber 13 for mixing. The air flowing into the mixing chamber 13 through the second air path 12 is humidified and belongs to relatively humid air, which is used as the wet air for mixing.

[0036] By controlling the mixing ratio (such as the flow ratio) of the dry air and the wet air in the mixing chamber 13, air that simultaneously meets the requirements of the fuel cell power generation system's stack 10 in terms of total flow, temperature, and relative humidity can be obtained, that is, the flow rate of the mixed air supplied through the mixing chamber 13 is equal to the total air demand flow rate of the stack 10, the temperature of the mixed air is equal to the air demand temperature of the stack 10, and the relative humidity of the mixed air is equal to the air demand relative humidity of the stack 10. During the actual working process, the corresponding flow rate of the dry air (the first set flow rate), the flow rate of the wet air (the second set flow rate), the temperature of the dry air (the first set temperature), and the temperature of the wet air (the second set temperature) can be inversely deduced (or directly obtained according to the pre-calibrated corresponding relationship) based on the total air demand flow rate, the air demand temperature, and the air demand relative humidity of the fuel cell power generation system's stack 10. By performing corresponding control on the first air cooling device 112, the dry air can be cooled to the first set temperature. By adjusting the temperature of the humidifying water in the humidifying tank 120, the air entering the humidifying tank 120 can be cooled to the second set temperature and humidified to obtain wet air at the second set temperature. For the convenience of implementing the above solution, preferably, the air is humidified to the water saturation state in the humidifying tank 120, that is, at 100% relative humidity, so as to obtain wet air at the second set temperature and 100% relative humidity. It is worth mentioning that since the humidity of the dry air is affected by the air humidity of the external environment, in order to accurately control the humidity of the mixed air, it can be implemented in combination with the air humidity of the external environment. Of course, for the simplicity of the solution, the influence of the air humidity of the external environment can also be ignored, and the relative humidity of the dry air is defaulted to 0%.

[0037] Specifically, the air supply system for the fuel cell power generation system further includes a first temperature sensor 113 and a second temperature sensor 123. The first temperature sensor 113 is disposed in the first air path 11 and located between the first air cooling device 112 and the mixing chamber 13, and is used to obtain the actual temperature of the dry air. The second temperature sensor 123 is disposed in the second air path 12 and located between the humidifying tank 120 and the mixing chamber 13, and is used to obtain the actual temperature of the wet air. Thus, the first air cooling device 112 is controlled according to the first set temperature and the actual temperature of the dry air, so that the temperature of the dry air is reduced to and maintained at the first set temperature. The temperature of the humidifying water in the humidifying tank 120 is adjusted according to the second set temperature and the actual temperature of the wet air, so that the temperature of the wet air is reduced to and maintained at the first set temperature.

[0038] By adjusting the rotation speed of the first air compressor 111, the air flow rate of the first air path 11 can be adjusted, and further the flow rate of the dry air can be adjusted, so that the flow rate of the dry air reaches and is maintained at the first set flow rate. Correspondingly, by adjusting the rotation speed of the second air compressor 121, the air flow rate of the second air path 12 can be adjusted, and further the flow rate of the wet air can be adjusted, so that the flow rate of the wet air reaches and is maintained at the second set flow rate. Specifically, the air supply system for the fuel cell power generation system further includes a first flow meter 114 and a second flow meter 124. The first flow meter 114 is disposed in the first air path 11 and is used to obtain the actual air flow rate of the first air path 11. The second flow meter 124 is disposed in the second air path 12 and is used to obtain the actual air flow rate of the second air path 12. Thus, the rotation speed of the first air compressor 111 is adjusted according to the first set flow rate and the actual air flow rate of the first air path 11, and the rotation speed of the second air compressor 121 is adjusted according to the second set flow rate and the actual air flow rate of the second air path 12.

[0039] Those skilled in the art can understand that the air supply system for the fuel cell power generation system uses two small air compressors (the first air compressor 111 and the second air compressor 121) to supply air and control the flow rate for the first air path 11 and the second air path 12 respectively, so as to replace the scheme of using a complete set of compressed air centralized supply system for air supply in the prior art and using two mass flow controllers to control the flow rates of the two air paths, which can reduce costs.

[0040] To filter impurities in the air of the external environment, the air supply system for the fuel cell power generation system further includes a first air filter 115 and a second air filter 125. The first air filter 115 is disposed in the first air passage 11 and upstream of the first air compressor 111, and the second air filter 125 is disposed in the second air passage 12 and upstream of the second air compressor 121.

[0041] Air can be humidified in the humidifying tank 120 by means of bubble humidification and / or spray humidification. Since the humidified air finally enters the stack 10 of the fuel cell power generation system to participate in the electrochemical reaction, it is necessary to ensure that the humidifying water in the humidifying tank 120 has a low conductivity (low concentration of conductive ions). Therefore, the humidifying water in the humidifying tank 120 is deionized water. The air supply system for the fuel cell power generation system further includes a humidifying water circulation path 14, a water pump 141, and a humidifying water cooling device 142. The two ends of the humidifying water circulation path 14 are respectively connected to the humidifying tank 120. The water pump 141 and the humidifying water cooling device 142 are both disposed in the humidifying water circulation path 14 so that the humidifying water in the humidifying tank 120 can circulate through the humidifying water circulation path 14 and flow through the humidifying water cooling device 142 during the circulation process to achieve cooling. It can be understood that the air compressed and heated by the second air compressor 121 can transfer heat to the humidifying water in the humidifying tank 120 after flowing into the humidifying tank 120, causing the temperature of the humidifying water to rise and the temperature of the air to drop to the second set temperature. Then, the heated humidifying water is cooled by the humidifying water cooling device 142. It is worth mentioning that the humidifying water cooling device 142 can be a radiator or a heat exchanger. Preferably, the humidifying water cooling device 142 is implemented as a plate heat exchanger. It is also worth mentioning that in order to maintain the humidifying water in the humidifying tank 120 at a low conductivity level, a deionizer (not shown in the figure) can also be provided in the humidifying water circulation path 14.

[0042] Since the humidifying water in the humidifying tank 120 is continuously consumed, the air supply system for the fuel cell power generation system further includes a water replenishing path 15, which is connected to the humidifying tank 120 and used to replenish humidifying water into the humidifying tank 120. In addition, the air supply system for the fuel cell power generation system may further include a drainage path 16, which is used to drain a part of the humidifying water when there is too much humidifying water in the humidifying tank 120 (such as when too much water is replenished through the water replenishing path 15).

[0043] Those skilled in the art can understand that the humidifying tank 120 for the fuel cell power generation system is used for humidifying and cooling the air, rather than heating and warming the air by using a humidifying tank as in the prior art. There is no need to configure a heating device for heating the humidifying water in the system, and the heat of the air compressed and heated by the air compressor can be fully utilized. In other words, in the prior art, a complete set of compressed air centralized gas supply system is used for gas supply, and the compressed air is cooled as a whole to a relatively low temperature by a cold dryer, and then divided into two paths. One path is humidified and heated by the humidifying tank, and the other path has a constant temperature. Finally, they are mixed, resulting in a process of the air cooling first and then heating, causing energy waste. In the present utility model, in the two air paths, after the air is compressed and heated by their respective air compressors, it is directly cooled to their respective set temperatures without going through the process of cooling first and then heating, and the energy can be fully utilized.

[0044] Referring to the attached drawings of the specification of the present utility model Figure 2 , an air supply system for a fuel cell power generation system according to another embodiment of the present utility model is illustrated. The difference between this embodiment and the above embodiment is that the air supply system for the fuel cell power generation system may further include a second air cooling device 122, wherein the second air cooling device 122 is disposed in the second air path 12 and located between the second air compressor 121 and the humidifying tank 120, so that the air compressed and heated by the second air compressor 121 can be preliminarily cooled by the second air cooling device 122 first, and then flow into the humidifying tank 120 to be further cooled to the second set temperature, so as to use the second air cooling device 122 to share a part of the burden of cooling the air for the humidifying tank 120. It is worth mentioning that the second air cooling device 122 may be an intercooler, a radiator or a heat exchanger. Preferably, the second air cooling device 122 is implemented as an intercooler.

[0045] Those skilled in the art can understand that the above embodiments are only examples, and the features of different embodiments can be combined with each other to obtain embodiments that are easily conceivable according to the content disclosed in the present invention but not clearly pointed out in the drawings.

[0046] Those of ordinary skill in the art should understand that the above description and the embodiments shown in the drawings are only for exemplarily explaining the present utility model, rather than limiting the present utility model. All equivalent implementations, modifications and improvements within the spirit of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An air supply system for a fuel cell power generation system, characterized in that, Comprising: A mixing chamber adapted to communicate with the air inlet of the stack of a fuel cell power generation system; A first air passage, one end of which is in communication with the external environment and the other end of which communicates with the mixing chamber; A second air passage, one end of which is in communication with the external environment and the other end of which communicates with the mixing chamber; A first air compressor disposed in the first air passage; A second air compressor disposed in the second air passage; A first air cooling device disposed in the first air passage and located between the first air compressor and the mixing chamber; And A humidifying tank disposed in the second air passage and located between the second air compressor and the mixing chamber, wherein the humidifying tank is used for humidifying and cooling the air flowing into the humidifying tank.

2. The air supply system for a fuel cell power generation system according to claim 1, characterized in that, The temperature of the humidifying water in the humidifying tank is not higher than the temperature of the air flowing into the humidifying tank.

3. The air supply system for a fuel cell power generation system according to claim 2, wherein It further comprises a humidifying water circulation path, a water pump and a humidifying water cooling device, wherein both ends of the humidifying water circulation path are respectively in communication with the humidifying tank, and the water pump and the humidifying water cooling device are both disposed in the humidifying water circulation path.

4. The air supply system for a fuel cell power generation system according to claim 3, characterized in that, The humidifying water cooling device is a plate heat exchanger.

5. The air supply system for a fuel cell power generation system according to any one of claims 1-4, characterized in that, It further comprises a first temperature sensor and a second temperature sensor, wherein the first temperature sensor is disposed in the first air passage and located between the first air cooling device and the mixing chamber, and the second temperature sensor is disposed in the second air passage and located between the humidifying tank and the mixing chamber.

6. The air supply system for a fuel cell power generation system according to any one of claims 1-4, characterized in that, It further comprises a first flowmeter and a second flowmeter, wherein the first flowmeter is disposed in the first air passage and the second flowmeter is disposed in the second air passage.

7. The air supply system for a fuel cell power generation system according to any one of claims 1 to 4, characterized in that, It further comprises a water replenishing path which is in communication with the humidifying tank and used for replenishing humidifying water into the humidifying tank.

8. The air supply system for a fuel cell power generation system according to any one of claims 1-4, characterized in that, The first air cooling device is an intercooler.

9. The air supply system for a fuel cell power generation system according to any one of claims 1 to 4, characterized in that, It further comprises a second air cooling device, wherein the second air cooling device is disposed in the second air passage and located between the second air compressor and the humidifying tank.

10. The air supply system for a fuel cell power generation system according to claim 9, characterized in that, The second air cooling device is an intercooler.

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